Efficient purification technology of bentonite

Bentonite is a multifunctional non-metallic mineral that plays an important role in many fields with its unique layered structure and excellent physical and chemical properties. This silicate mineral has been widely used in metallurgy, casting, environmental protection, chemical industry and other industries due to its expansibility, adhesion, adsorption and other characteristics.

The content of montmorillonite, the main component of bentonite, is the key factor in determining its industrial value. Bentonites produced in different regions require different purification processes due to their different components. With the rapid development of my country's bentonite industry, it is currently dominated by low-end and medium-end products, and industrial upgrading is imminent. In order to achieve high-end development, it is necessary to increase the montmorillonite content through purification technology to make full use of the excellent properties of bentonite.

The methods for purifying bentonite are mainly divided into two categories: dry method and wet method. Dry purification, that is, air separation, is suitable for the separation of non-clay minerals with large hardness and particle size. Through the cyclone dust collector, the density and hardness differences are used for graded purification. The advantage of dry purification is that the montmorillonite content is high and the recovery rate is also high, especially suitable for high-quality mining areas with high montmorillonite content.

Wet purification is aimed at the generally low-grade bentonite in my country. The grade of bentonite is improved through natural sedimentation, centrifugation, flocculation, ultrasound and cyclone classification. The natural sedimentation method uses the characteristics of bentonite swelling by absorbing water to separate it from non-swelling impurities by preparing a certain concentration of slurry. The centrifugation method separates the supernatant through centrifugal motion to obtain high-purity montmorillonite. The flocculation method uses flocculants to aggregate and precipitate montmorillonite with tiny particles, and then removes the flocculants through deflocculation to obtain high-purity concentrate.

For impurities with extremely fine particle size and tightly bound to montmorillonite, physical methods are difficult to remove, so chemical purification is particularly important. Chemical purification uses chemical reagents such as strong alkali to separate impurities from montmorillonite and improve the purity of bentonite. It is especially suitable for the production of high value-added products such as medicines.

Taking into account the production cost and product application requirements, selecting the appropriate purification process or the combined use of multiple processes can effectively improve the product quality of bentonite, reduce production costs, and promote the high-end and rational development of the bentonite industry.